You'd be surprised how many replica airguns there are. A lot are made by Umarex.

Umarex seem to lead the pack in terms of realistic replicas in terms of air guns. I have the Walther PPK/S and P99 Compact, the Beretta Px4 Storm pistol, and Beretta Cx4 Storm Carbine. While I don't have access to the real steel to compare them directly, comparing pics of the real guns to my air guns, they seem to be some really close matches. These pistols are all GBB too, which maked their operation just as realistic as an airsoft pistol. It's a very unfair law, to say the least.